三维石墨烯-碳纳米管/水泥净浆的压敏性能

Piezoresistivity of three dimensional graphene-carbon nanotubes/cement paste

  • 摘要: 为了探索三维石墨烯-碳纳米管(G-CNTs)/水泥净浆的压敏性能,采用四电极法研究了荷载作用下G-CNTs/水泥净浆的电阻率变化,并分析不同G-CNTs掺量、加载幅度、加载速度以及恒定荷载对电阻率变化的影响。研究表明:随着G-CNTs掺量的增加,电阻率呈先减小后稳定的变化趋势,在G-CNTs掺量由0.2wt%增加至1.6wt%时,电阻率下降51.8%;电阻率与温度呈负相关;G-CNTs掺量高于0.8wt%时可以显著提高水泥净浆的压敏性能,且电阻率变化率与应力应变有明显的对应关系,1.2wt%G-CNTs掺量下试件的应力灵敏系数和应变灵敏系数分别为2.3%/MPa和291;G-CNTs/水泥净浆电阻率变化率幅值随着加载幅度增大而相应增加,其电阻率变化率曲线在不同加载速度以及恒定荷载作用下均与应力-应变曲线一一对应,具有良好的压敏特性。

     

    Abstract: In order to explore the piezoresistivity of three dimensional graphene-carbon nanotubes (G-CNTs)/cement paste, the four-electrode method was used to study the resistivity change of the G-CNTs/cement paste under load. The influence of G-CNTs content, loading amplitude, loading speed and constant load on the resistivity change was analyzed. The results show that the resistivity decreases first and then tends to stabilize with the increase of the G-CNTs content. When the G-CNTs content increases from 0.2wt% to 1.6wt%, the resistivity decreases by 51.8%. The resistivity is negatively correlated with temperature. When the G-CNTs content is higher than 0.8wt%, the piezoresistivity of the cement paste is significantly improved, and the rate of change in resistivity has an obvious corresponding relationship with the stress-strain. The stress sensitivity coefficient and the strain sensitivity coefficient of the specimens with 1.2wt% G-CNTs are 2.3%/MPa and 291, respectively. The amplitude of the rate of change in resistivity of G-CNTs/cement paste increases as the loading amplitude increasing. The rate of change in resistivity curve corresponding to the stress-strain changes under different loading speeds and constant load exhibits good piezoresistivity.

     

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